Defrost indicator for refrigerators



Nov. 25, 1952 A. G. JANOS ET AL DEFROST INDICATOR F 'OR REFRIGERATOR-3Filed NOV. 30, 1950 .Qm/Y 8 6 am m 6 t E 0 F .W a m A T Patented Nov. 251952 DEFROST INDICATOR FOR REFRIGERATORS Alfred G. Janos, Erie, Pa., andJames L. Knight, Bridgeport, Conn., assignors to General ElectricCompany, a corporation of New York Application November 30, 1950, SerialNo. 198,416

7 Claims.

This "invention'relates to refrigerators and more particularly :todefrost indicators for refrigerators.

The cooling unit :or evaporator in many household refrigerators isexposed to the air in the food storage compartment and, because of thelow temperature of the evaporator, moisture in the air in the storagecompartment condenses on the evaporatorv and forms frost. To maintainthe refrigerating apparatus operating at a relatively high efficiency,it is necessary to remove this frost from time to time. In order toindicate to the user when the amount of frost collected is such that theevaporator should be defrosted, some form of indicating or signallingdevice may be employed. To impress the need for defrosting more forciblyupon the user, it is advantageous to employ a defrost indicator whichprovides a live signal, that is, an indicator which moves in the area ofthe users vision during his use of the refrigerator. Accordingly, anarrangement is provided whereby, when the frost is of some particularthickness, an indicating element is positively moved into an exposedposition in clear view of the user. This makes it more difiicult for theuser to overlook the need for defrosting than in a case where a staticindicator is employed.

It is an object of this invention to provide an improved arrangement forindicating the thick- .ness of frost collected on a cooling .unit orevaporator.

It is another object of this invention to provide an improvedarrangement for indicating when the frost on the cooling unit hasreached .a predetermined maximum thickness.

It is a further object of this invention to provide an improvedarrangement associated with y In carrying out the objects of thisinvention a pivoted element is mounted on the evaporator in such' amanner as toengage the frost on one of the walls of the evaporator whenthe door is moved to its open position. The pivoted element isresiliently biased toward its frost-engaging position, and it includesan indicating portion normally concealed by a portion of the door andmovable to an exposed position by a predetermined thickness of frostwhen the evaporator door is in its open position.

For a better understanding of this invention reference may be had to theaccompanying drawings in which Fig. 1 isa view of a portion of arefrigerator illustrating an embodiment of this invention; Fig. 2 is anenlarged sectional view of the defrost indicator of Fig. 1, showing theindicator in its normal concealed position; Fig. 3 is a view similar toFig. 2 showing the indicator in an exposed position; Fig. 4 is anenlarged perspective view of the pivoted indicating element;

. Fig. 5 is a view similar to Fig. 2 showing the modified form of thisinvention; and Fig. 6 is a view similar to Fig. 5 showing the modifiedform of indicating element in its exposed position.

Referring now to the drawing there is shown a refrigerator I including afood storage compartment 2 and an evaporator or cooling unit 51, mountedin the upper portion of the food storage compartment for cooling thiscompartment. The front of the evaporator 3 is closed by a door 4 whichis hinged, as indicated at 5, to one side of the evaporator 3.

In order to indicate the amount of rost collecting on the evaporator 3and thereby to indicate the need for defrosting, a defrost indicator 6is mounted on the door 4. This defrost indie cator is shown in greaterdetail in Figs. 2, 3 and The indicator includes a plate 1 which issecured by screws 8 or other suitable fastening devices to the body ofthe door 4. A pivoted indicatin element 9 is mounted on the plate I by apin It. The indicating element 9 includes an arm I] which is adapted toengage frost collecting on the side wall l2 of the evaporator 3. Theelement 9 is biased in a direction in which the arm ll engages the frostby a spring 13. The ends of the spring l3 are received within cup-shapedreceptacles l4 and 15 formed in the plate I and the pivoted element 9respectively. In order to provide a visible element for indicating tothe user the amount of frost collected on the evaporator, the pivotedelement 9 includes an indicating portion I6 at the opposite end from thefrostengaging arm i I. The door 4, which is preferably molded from somesuitable plastic material, is formed with any upstanding rib l1 adjacentthe indicating portion N5 of the pivoted element 9. When the indicatingelement 9 is in the position shown in Fig. 2, that is, when there issubstantially no frost on the evaporator 3, the indicating portion I6 issubstantially concealed from the users view by the rib I! of the door.

In order to limit the opening movement of the door 4 to the positionshown, a rubber bumper I8 is mounted between the inner liner IQ of therefrigerator cabinet and a breaker strip 29 which closes the spacebetween the inner liner l9 and the outer wall 2| of the refrigeratorcabinet adjacent the access opening of the refrigerator cabinet. Sincethe pivoted element 9 is biased by the spring 13 in a counter-clockwisedirection, each time the evaporator door 4 is opened the arm ll of thepivoted element 9. is brought.

into engagement with the frost collected on the wall [2 of theevaporator}, Since the open position of the door 4 is fixed by itsengagement with the rubber bumper l8, the position of the pivotedelement 9 and, hence, of its indicating portion I6, isdetermined by theamount of frost on the. side wall l2 of the eVaPQ Tator. In the positionshown in Fig. 2, for example, where there: is substantially no' frost.collected, the indicating portion [6 of the pivoted element 9 issubstantially concealed by the'upstanding rib or member I! on the do'or4.. Onthe other hand,

I under lthelcondition shown in Fig. 3 where a substantial amount of,frost 22 has collected on the evaporator 3, the pivoted element 9. hasbeen shifted in a counterclockwise direction against the. bias of the,springfl3, by the engagement of the arm ll w'ithf the relatively thicklayer of frost 2-2, 1 Underthis condition the, indicating portion'il-fi.of. the pivoted element' {extends a substantial. distance, beyond theend of the rib l6 and? hence,'the face "the'reofis exposed 'to the usersView. The front face of the indicating portion 11$. may be.inscribed'with a suitable legend such as fDefrostfi crlit may merely beaintedlwith .someic'onspicu'ous color, such as red; so asito'attract theusers attention readily. Further, since the distance, which the.indicatin p iq f. fl 6 extends eyond the rib U115. di-

. rectly ideplendent upon-the varying thickness of fies t m the: c rz ior; the. ace Of themdicati'ngf portionfn'iay, if desired; bcflinscribedwith suitable marking so thattheexact'thickness of. the frost can benotedlbyj iihfi userj thus inscriptions ch a A337; 7 /4; tc m y beplacedontheface 'Of the indicating portion I6, and-the user ca n' th'enncte the thickness of frost t i ialiora r y n h numera whi p aadiaic'ent hc ronti'ed e c ,v the ib' In theform of defrost indicatorjust described it has been. pointed out that "the position of thepivoted'element 9', and, hence, f the indicating portion l6. in the;open position 10f 'the.'door 4 varies directly andv progressively withthe thickness of the frost :22 on the evaporator 3. In Figs. 5'and'6there is shown a modified form of this invention whichdiffers from thatpreviously described in that the indicating portion is concealed fromview until the frost has reached a predetermined thickness at whichdefrosting is desirable for efficiento'peration of the refrigeratingapparatus. The (same numerals have been used'to designate correspondingparts in Figs. 5 and ,6 and'in Eigs; 1 through 4 inclusive. Referring toFigs. 5 and 'G'there is shown an evaporatqr door 23, which is hinged, asindicated at 5, to ,the evaporator 'Ihe evaporatordoor 23 is formed ofmetal and isofa spaced walljconstruction including an outer wall 24andfan'inner wall 25 spaced therefrom.' In .order to 'pro vide anindication of the thickness of frost and,

4 hence, of the need for defrosting, a pivoted element 26 is mounted onthe door 23 by a pin 21. This pivoted element 26 includes an arm 28which is adapted to engage frost collecting on the side wall I2 of theevaporator 3. The pivoted element 2Q further inmludes an indicatingportion 29 at the oppbsitend thereof, this indicating portion servingthe same function as the portion I6 of the pivoted element 9 in the formpreviously described. The inner wall 25 Iof .tbeldoor 23 is shaped toprovide an opening io ,fd .9siin a-. ea fii i eme rid to snapfrom one tothe other under 'prdete'rmined fconditi'ons, -'a"'-snajp -adn*g qvereehtr m chanis ,1 'is c i sl'ee E oroth'erwise s ed an he s de al 12 1 2c eva ii Acco dingly wheeliesth ngs- Wired 'tQ its tic po io "r bciar i awill readilyf'notice' 1 thfpioc ss br placing things or taking articlesrr'omytnee'vapb atoi and because of the flive eflect of he nievement ofthe 0? i pcnt h for defrosting is unlikel defrosting the user may returnthe indicator to the position shown in Fig. 5 by pressing on the exposedend of the indicating portion 29.

While for convenience the representation of the bumper l8, the innerliner I9 and the breaker strip 20 has been omitted from the illustrationin Figs. 5 and 6, it will be obvious that this arrangement for limitingthe movement of the door in its open position is also employed in thearrangement illustrated in Figs. 5 and 6.

While specific embodiments of this invention have been shown anddescribed, it is not desired that this invention be limited to theparticular constructions shown and described and it is intended, by theappended claims, to cover all modifications within the spirit and scopeof this invention.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. In a refrigerating apparatus including a cooling unit upon whichfrost collects, a door for said cooling unit hinged for movementrelative thereto, means for indicating the frost collected on saidcooling unit, said means including a pivoted element mounted on saiddoor at the hinged side thereof, said pivoted element including an armmoved toward said frost when said door is moved to its open position,and means for biasing said arm toward said frost, said pivoted elementfurther including an indicating portion normally concealed and movableinto an exposed position dependent upon the amount of frost on saidcooling unit.

2. In a refrigerating apparatus including a cooling unit upon whichfrost collects, a door for said cooling unit hinged for movementrelative thereto, means for indicating the frost collected on saidcooling unit, said means including a pivoted element mounted on saiddoor at the hinged side thereof, said pivoted element including an armprojecting beyond said door and moved toward said frost when said dooris moved to its open position, and means for biasing said arm towardsaid frost, said pivoted element further including an indicating portionnormally concealed and movable into an exposed position dependent uponthe amount of frost on said cooling unit.

3. In a refrigerating apparatus including a cooling unit upon whichfrost collects, a door for said cooling unit hinged for movementrelative thereto, means for indicating the frost collected on saidcooling unit, said means including a pivoted element mounted on saiddoor at the hinged edge thereof, said pivoted element including anindicating portion, means for biasing said element in one directionwherein said indicating portion is concealed by said door, said pivotedelement including an arm engaging the frost on said cooling unit whensaid door is moved to its open position whereby said pivoted element ismoved against its bias to force said indicating portion into an exposedposition when said frost reaches a predetermined thickness.

4. In a refrigerating apparatus including a cooling unit upon whichfrost collects, a door for said cooling unit hinged for movementrelative thereto, means for indicating the frost collected on saidcooling unit, said means including a pivoted element mounted on saiddoor at the hinged side thereof, said pivoted element includin an armmoved toward said frost when said door is moved to its open position,and means for biasing said arm toward said frost, said pivoted elementfurther including an indicating portion, said door including a memberpositioned adjacent said indicating portion for concealing saidindicating portion, said indicating portion being moved, when said dooris opened, into an exposed position beyond said member by an amountdependent upon the amount of frost on said cooling unit.

5. In a refrigerating apparatus including a cooling unit upon whichfrost collects, a door for said cooling unit hinged for movementrelative thereto, means for indicating the frost collected on saidcooling unit, said means including a pivoted element mounted on saiddoor at the hinged side thereof, said pivoted element including an armmoved toward said frost when said door is moved to its open position,and means for biasing said arm toward said frost, said pivoted elementfurther including an indicating portion normally concealed and movable,when said door is opened, to an exposed position by an amount dependenton the amount of frost on said cooling unit.

6. In a refrigerating apparatus including a cooling unit upon whichfrost collects, a door for said cooling unit hinged for movementrelative thereto, means for indicating the frost collected on saidcooling unit, said means including a pivoted element mounted on saiddoor at the hinged side thereof, said pivoted element including an armmoved toward said frost when said door is moved to its open position,and means for biasing said arm toward said frost, said pivoted elementfurther including an indicating portion normally concealed and movable,when said door is opened, into an exposed position when the frost onsaid cooling unit exceeds a predetermined amount.

'7. In a refrigerating apparatus including a cooling unit upon whichfrost collects, a door for said cooling unit hinged for movementrelative thereto, means for indicating the frost collected on saidcooling unit, said means including a pivoted element mounted on saiddoor at the hinged side thereof, said pivoted element including an armmoved toward said front when said door is moved to its open position,said pivoted element further including an indicating portion, and anoveroenter spring for normally biasing said element to a positionwherein said indicating portion is concealed, said spring bein movedover center to snap said indicating portion to an exposed position uponopening of said door when the frost on the cooling unit exceeds apredetermined amount.

ALFRED G. JANOS. JAMES L. KNIGHT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,999,191 Hirschl Apr. 30, 19352,112,261 Backstrom Mar. 29, 1938

